Motorola RDX Series software can be found by visiting the Motorola Solutions website, finding your radio, and clicking on the resources tab. The RDX Series software tab can be found midway down the left side of the page.
The Motorola RLN6303 will clone the following Motorola two way radios:
RDU2020, RDV2020, RDU2080D, RDV2080D, RDM2020, RDM2080D, RDU4100, RDU4160D, RDV5100, CP110